I have tried this, then it did not get appended to the snapshot.But in a you tube video, it was told that, "when we make updations to the source database, then sql server performs copy on write process and updates the snapshot database immediately."

So please help me out in understanding the actual things happening behind.

database snapshot is a symbol of integrity. Normally after creation of a snapshot, if any new object is added to that database,then that one is not added to the snapshot which is created earlier.The snapshot which is created earlier will remain same from the time of creation.

What happens actually with the creation of database snapshot is,assume that the size of the database is some 12MB.Now when the snapshot is created, the number of pages that are involved in database for storing data will be counted.

The same number of pages will be allocated for the snapshot. But the original data will not be moved to these data pages of snapshot.The data will be copied from pages of original database to those of snapshot database only when these data pages of original database gets modified. This is what means "Copy On Write" process.